A Validation Model for Measurement of Acetabular Component Position

There is no agreement on a standard approach to evaluating acetabular cup orientation, ideal target orientation, or a standardized measurement method for cup orientation in total hip arthroplasty. The purpose of this study was to investigate a simple method for validating measurements of acetabular orientation obtained using computer navigation and computed tomography scans. This study validated the imageless navigation system to be accurate with a precision of 1° and a bias of 0.02° for inclination and a precision of 1.3° and a bias of 0° for anteversion measurements. From this study, we propose that acetabular cup alignment is accurately assessed using computer navigation. We suggest acetabular orientation be reported in the radiographic plane (coronal plane), which incorporates pelvic tilt and therefore is more functional definition of cup position.